Flight simulators are one of the most common motion simulation systems in use today and are capable of re-creating aircraft flight and different aspects of the flight environment. Flight simulators are employed for flight training, the design and development of aircraft, control handling evaluation and other purposes. Depending on the purpose of a particular system, flight simulators can range in complexity from PC-laptop models to full flight simulators employing replicas of an aircraft cockpit including controls, aircraft systems and wide-field outside-world (OTW) visual systems all mounted on six degree-of-freedom motion platforms which move in response to control commands from the cockpit and external aerodynamic forces. These motions include three linear movements, namely heave (up and down), surge (fore and aft) and sway (side-to-side), and, three rotational movements including pitch (rotation about the sway axis), yaw (rotation about the heave axis) and roll (rotation about the surge axis).
In addition to motion platforms, flight simulators may include one or more motion seats intended to replicate the pilot and co-pilot seats of a particular aircraft. Motion seats comprise a seat pan and a seat back which collectively are capable of providing surge, sway, heave and roll movements, independently of but in coordination with, the motion platform on which the motion seats are mounted. In most current motion seat designs, the seat pan undergoes heave and roll motions while surge and sway movements are produced by the seat back. Typically, one actuator is required, on both the left-hand and right-hand sides of the seat pan, to effectuate a heave motion, and another actuator on each side of the seat pan is operative to produce roll left or roll right motion, as the case may be. This construction is cumbersome, expensive, relatively complex and inefficient. Additionally, the seat pan of currently available motion seats has no capability to move in a fore and aft direction to complement the surge motion provided by the seat back.